It looks like it might need a special tool because of that angled cut on the face of the cylinder head. I know Laylax makes a special wrench to tighten their own Laylax cylinderheads for bolt action rifles, but their wrenches won't fit PDI cylinder heads. Additionally, I already asked PDI (directly on their Xfire website) if they sell a tool to tighten their cylinder heads, but I didn't receive a response.
